# Math Help - Find the DE that is consistent with this method

1. ## Find the DE that is consistent with this method

How do I find a DE that is consistent with:

$u_j^{n+1}=\frac{1}{2}(u_{j+1}^n+u_{j-1}^n)-\frac{1}{2}\frac{\Delta t}{(\Delta x)^3}(u_{j+2}^n-2u_{j-1}^n-u_{j-2}^n)$

Also, when is the scheme stable?

2. ## Re: Find the DE that is consistent with this method

Are you sure about that $(\Delta x)^{3}$ ?

Yes I am :\

4. ## Re: Find the DE that is consistent with this method

Too bad, $(\Delta x)^{2}$ and I could probably offer some help. I'm not familiar with methods involving $(\Delta x)^{3}$.

5. ## Re: Find the DE that is consistent with this method

can you offer your help for the x^2? And I'll see what I can do to change it for x^3?

6. ## Re: Find the DE that is consistent with this method

It's just textbook stuff. Look at the section on the solutions of parabolic equations.